


Coefficient of Relationship

by Lauren (notalwaysweak)



Series: Consanguinity [5]
Category: The Big Bang Theory (TV)
Genre: Additional Warnings Apply, Community: trope_bingo, F/M, Forbidden Fruit, Sibling Incest, consensual incest
Language: English
Status: Completed
Published: 2014-05-03
Updated: 2014-05-03
Packaged: 2018-01-21 18:24:46
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,452
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1559783
Author URL: https://archiveofourown.org/users/notalwaysweak/pseuds/Lauren
Summary: <blockquote class="userstuff">
              <p>Their birthday comes but once a year, and sometimes they're states apart, but sometimes circumstances conspire to bring them together. Please read the tags and consider your squicks/triggers before continuing.</p>
            </blockquote>





	Coefficient of Relationship

**Author's Note:**

> The Big Bang Theory characters do not belong to me and I am not making any money off this work of fan fiction, unless maybe someone pays me to just stop already.
> 
> Written for Trope Bingo, for the 'forbidden fruit' square. (11/25 squares filled and only one line completed; I am clearly doing something wrong.)
> 
> Betaed by damalur, who does more than she realises to put the finishing touches on these things for me, and who encourages me, also perhaps more than she realises, even if it's just by shouting 'LANNISTERS' at me over Tumblr.
> 
> * * *

“I don’t get it,” Penny said yet again; the repetition was irritating Sheldon, as was the topic of discussion. “I mean, sure, everyone’s saying he raped her, but isn’t it a big enough deal that they’re related in the first place?”

Leonard spoke up before Sheldon could say anything. “One of the things they deliberately point out is that incest wasn’t unusual in the society at the time. There’s three hundred years of precedent in House Targaryen–”

“But it’s not based on a real society anyway. It’s _fantasy_. He could have written the books without all of the sketchy sex stuff.”

“Their biological relationship isn’t the issue,” Sheldon said. “The trouble with the televised adaptation is the lack of consent. Jaime didn’t force himself on Cersei in the book. In fact, her consent was quite enthusiastic.”

“Uh.” Penny looked at Missy. “You got any thoughts on this?”

“Just don’t expect to ever hear me say, ‘Fuck me, brother’,” Missy said, and everyone laughed, diffusing the tension in the room.

“Who gets to decide what counts as sketchy sex stuff, anyway?” Raj asked. “It’s not that long since people used to think being gay was a mental illness. Or there’s age gaps in relationships.”

“You’re just saying that so we’ll all say how happy we are – _again_ – that you finally settled down with your man-cougar,” Bernadette said.

“Roar,” Stuart said dryly, provoking another round of laughter.

* * *

 

The group went their separate ways some time later; Howard and Bernadette to their apartment, Raj and Stuart to theirs–

(“Eight years isn’t _that_ big an age gap, and if you call me December again I’m moving back into the stockroom!”)

–Amy to her own place, and Leonard and Penny across the hall to Penny’s.

("So, Penny–"

"I'm not calling you Daddy, Leonard, forget it.")

Leonard had been only too eager to clear out for a few nights so that Missy could use his room.

There was no way that either Sheldon or Missy could have explained to him that it wouldn’t be necessary. Or rather, _why_ it wouldn’t be necessary.

They took their turns showering: Sheldon first, then Missy. When she came to bed her hair was still damp. She wore a thin, clinging pink camisole and matching shorts. Her tummy was still a little rounded post-baby; her breasts were heavier than usual, her nipples dark peaks pushing at the cotton. She slid into bed beside Sheldon and rolled straight into his arms.

“I’m glad you could come up here,” Sheldon said.

“It’s a relief to take the break. I should feel bad sayin’ that about my own child and husband, but really, it is.”

“You can rest here, if you want. Whatever you want.”

Missy smiled. “Oh? Is that so?” She hooked her leg over his and pressed close against him, and Sheldon laughed softly even as their lips met. Missy would always get her way with him. Get it and have it.

He tried to be as gentle as possible, up until the point Missy said, “For heaven’s sake, Shelly, I ain’t that fragile.” Then he dragged her camisole off and bent his head to her breast, and heard her reaction, a mixture of a laugh and a gasp.

Biology being what it was, his mouth was shortly filled with sweetness; he thought there was an undertone of almonds. Despite what he’d been told, he went easy on her; he knew how this could hurt. If she was in pain, though, she wasn’t saying as much. Her fingernails on the back of his neck were saying exactly the opposite.

A low chime sounded from the nightstand and Sheldon lifted his head to speak, only to hear Missy beat him to it: “Happy birthday.”

“This is far past my bedtime,” he said instead.

“I have a four month old. What’s bedtime?”

Sheldon smiled and returned his attention to her breasts, until Missy’s back was arching, her breathing uneven. When he slipped a hand between her thighs and cupped the soft curve of her mons veneris, even before his fingers pressed closer in, her breath stopped altogether for a moment.

She had always had an unconscious air of grace about her, even when she was panting and disheveled. The way that she lifted her hips to aid Sheldon in easing her shorts off was only one manifestation of it. The way that she caught at his hair as his lips and tongue found her center to taste her other kind of sweetness, that was less graceful, but Sheldon relished it. Since their earliest experiences together she had so often been the one to make him lose control; having a chance to reverse the balance of power was special.

“Shelly...” Missy didn’t have to say anything else. Sheldon slid a finger into her, finding her wet beyond what his mouth had done, and coupled the curling of his finger with a series of long licks that started at her entrance and dragged up to her clitoris, over and over until she made a noise that still somewhat resembled his name and he felt the slow ripples of pleasure rock her.

The next thing she said was, “Again?”

It never even occurred to Sheldon to demur.

* * *

 

They lay side by side some time later. Sheldon still wore his pyjama pants; Missy was unselfconsciously naked, stroking his chest. It was harder to dismiss the temptation of pleasure when it was so closely present. When she was in Texas, all Sheldon had to contend with was his feelings for Amy, which were a lot less well-defined and thus easier to ignore.

Missy had never been possible to ignore.

“Do you think we’ll ever outgrow each other?” Missy asked, unaware of how her question fit with Sheldon’s thoughts.

“No. Why?”

“Oh, no reason. It’s just nice to think there’s someone who’ll always be there.”

“Melissa. You _just_ had a child. I’m given to understand they’re usually in the picture for some time.”

Missy laughed, although he’d been serious, and her hand roved lower, quite effectively nipping Sheldon’s concerns in the bud. She didn’t speak again for some time, putting her mouth to other uses. They kissed slowly as she touched him, and then her lips drifted from his lips to the side of his neck, and from there down his chest. She rolled to straddle him, pressing down onto him, rubbing herself along his length, and Sheldon was infinitely grateful that the apartment was otherwise unoccupied. Even more so when she got his pants out of the way – her movements economical, his clumsy – and took him into the warmth of her mouth.

“Missy. Oh. God.” He tried to dissuade her, but she dug her fingernails into his thighs and Sheldon couldn’t bear to deny her what she was clearly enjoying. It wasn’t exactly a hardship: the slow rhythmic pull of her mouth, the soft brush of her hair across his thighs. When she did stop he was aware of making a disgruntled noise, and the answering music of her laughter.

His friends would have been shocked to know that Sheldon kept condoms in his nightstand at all, let alone why they were there. The thought crossed his mind that if he ever did invite Amy to his bedroom, he’d have to make sure the box wasn’t already half empty.

Then Missy was on him and he was in her and all thoughts of Amy fled.

Missy was moving slowly, holding back, and Sheldon could see the wicked look in her eyes. They had refined a lot of things over the years, learning from their mistakes, but the one mistake he let himself make time and again was underestimating her when she got that look. It usually meant that she had something particular in mind.

Sure enough, before long she shifted position, stretching each limb gracefully until she was lying atop him instead of straddling him, his cock still caught within her.

“Now roll,” she said, and Sheldon rolled them over, and watched the way Missy’s face went soft with pleasure as the new angle slid his length against her clitoris. He filed the position away for future reference, very briefly imagining Amy’s face with the same expression. The thought made him drive a little harder into Missy, and then she was coming, gasping his name.

When he came, he pressed his face down into Missy’s hair, the long waves tickling his nose and cheeks but comforting, especially the familiar scent of her. They had grown up and grown apart in many ways, but engulfed in her warmth all that time and distance condensed down to here and now.

“We be of one blood, ye and I,” Missy murmured, and Sheldon smiled. 

 


End file.
